It is this element of uncertainty in our ability to effect a standard modification of milk that has afforded manufacturers the rich opportunity of putting on the market various baby foods for which much is claimed. These foods are really substitutes for the inefficiency of the average mother. There is no real justification for their use. If all mothers were clean, faithful, and efficient, there is no reason why each one could not be taught to modify cow's milk to suit her child, just as satisfactorily, or more so, than a manufacturer who never saw her child. The manufacturers, however, do the work, and the naturally ignorant or lazy and inefficient mother, is willing to pay for the extra cost of labor, to save herself the trouble on the one hand, and to subject her child to a series of experiments in order to discover the manufactured food that is particularly adapted to her particular baby on the other hand. We believe that most mothers have never considered the question from this standpoint; that most mothers adopt this method of artificial feeding at the direct suggestion of their family physician, and are not, therefore, responsible. These foods do not contain the nutritional elements necessary to healthy growth; or as they exist in normal breast milk; or as they can be approximated in ordinary milk modification at home. Proprietary foods are of decidedly poor value in infant nutrition, and should not be used. They have a value, however, in certain diseased conditions, but within a very small range. As a food for a healthy growing infant, they should not be used, and when the average physician appreciates this fact, and so instructs the mothers of the country, it will be to the distinct advantage of the race in every respect. Proprietary foods to which fresh cow's milk is added, are not foods at all,--they depend upon the milk so far as any nutritional value is concerned; and it would be far safer to modify at home a good milk than to buy a proprietary food, the analysis of which cannot be depended upon. The credit for the fat, healthy babies we see advertised does not belong to the manufacturers, but to the cow whose milk you add to the manufacturer's sugar. The proprietary beef foods are also valueless as infant foods. In certain illnesses, when we want a mild stimulant, a teaspoonful or two in hot water may have a certain value, but that is all. The beef juice of home manufacture is much more valuable. DIFFERENCE BETWEEN HUMAN AND COW'S MILK.--The composition of cow's milk is as follows: Fat (represented by cream) 4% Sugar 4% Proteids (represented by curd) 4% The composition of an average human breast milk is as follows: Fat 4% Sugar 7% Proteids 1-1/2%